This invention relates to padlocks, and particularly to a padlock having a lock cavity for receiving a removable lock core. More particularly, the present invention relates to a retainer assembly for keeping a shackle-locking bolt of the padlock in a retained position in the padlock while the lock cavity is empty of a removable core.
Padlocks configured to accept removable lock cores are typically shipped to a destination with a shackle and bolt mechanism for locking the shackle but without a lock core for actuating the bolt mechanism. In many instances, these removable lock cores are shipped to the destination independent of the padlocks that will ultimately house them. Typically, wadded paper, foam, or other filler is inserted into the empty core-receiving cavity in the padlock to prevent the bolt mechanism from falling out of the padlock through the cavity during shipment. This conventional practice is unsatisfactory because it could lead to loss of the bolt mechanism or potential damage to the bolt mechanism or its components.
One object of the present invention is to provide a bolt mechanism that is retainable or immobilized in a padlock case during shipment of the padlock without its removable lock core.
Another object of the present invention is to provide a tool for releasing and removing the bolt mechanism from a secure position inside the padlock to disassemble the padlock for repair. This tool could also be used easily to install the retainable bolt mechanism in a secure position inside the padlock to assemble the padlock for shipping.
Yet another object of the present invention is to control the maximum rotation-inducing torque that can be applied to a torsion spring that is used to bias a rotary lock-actuating bolt in a padlock to guard against overstressing such a torsion spring during unlocking of the padlock.
Still another object of the present invention is to provide a subassembly comprising a bolt and a bolt-biasing spring that is easily installed in and removed from a lock case using a single tool in a swift manner to simplify and refine the manufacturability and repairability of a lock containing the subassembly.
According to the present invention, a removable core padlock includes a lock case formed to include a lock cavity configured to receive a removable core and a bolt-receiving cavity in communication with the lock cavity. A shackle is movable between locked and open positions relative to the lock case. Means is provided in the lock case for locking the shackle in its locked position, which locking means is movable between a shackle-locking position and shackle-releasing positions.
Bolt means is provided in the bolt-receiving cavity for moving the locking means from its shackle-locking position to a shackle-releasing position. Such movement occurs in response to operation of a removable core installed in the lock cavity. First spring means is also provided for yieldably urging the bolt means relative to the lock case to a position establishing the shackle-locking position of the locking means.
The padlock further includes second spring means for yieldably urging a portion of the bolt means relative to the lock case into removal-blocking engagement with an inner wall of the lock case. Such engagement of the bolt means and the lock case causes the bolt means to be retained in the bolt-receiving cavity in a retained, substantially immobile position while the lock cavity is empty of a removable core.
In preferred embodiments of the present invention, the bolt means is rotatable about an axis relative to the lock case and against the first spring means to move the locking means to its shackle-releasing position. Further, the second spring means is aligned to yield in a direction orthogonal to the axis of rotation of the bolt means upon rotation of the bolt means during removal of the bolt means from the bolt-receiving cavity.
The first spring means is illustratively a torsion spring positioned yieldably to rotate the bolt means about its axis of rotation. The second spring means is illustratively a compression spring positioned yieldably to urge said portion of the bolt means into engagement with said inner wall of the lock case in a direction orthogonal to the axis of rotation of the bolt means. Preferably, the first spring means is integrally connected to the second spring means.
A tool is also provided for manipulating the bolt means in the lock case. The tool includes a shaft extendable into the lock cavity when empty of a removable core. Means is also provided on the shaft for rotating the bolt means against the compression spring in response to rotation of the shaft in the lock cavity. This action withdraws said portion of the bolt means from engagement with the inner wall of the lock case so that the bolt means is released from a trapped position within the lock case. The tool further includes means on the shaft for extracting the bolt means from the bolt-receiving cavity and lock cavity in response to withdrawal of the shank from the lock case.
One feature of the present invention is provision of second spring means for yieldably urging a portion of the bolt means into removal-blocking engagement with an inner wall of the lock case. Insertion and removal of the bolt means into and from the padlock case is facilitated because of the yieldable character of the second spring means. This feature permits a technician to move said portion of the bolt means against the second spring means during insertion or removal of the bolt means without disrupting the retainability of the bolt means in the padlock. Advantageously, the bolt means itself engages the padlock case to retain the bolt means therein while the lock cavity in the padlock is empty of a removable core during shipment without resorting to any extraneous cavity "filler" such as wadded paper or the like.
Another feature of the present invention is that the second spring means is integrally connected to first spring means provided in the padlock for yieldably urging the bolt means to a position establishing the shackle-locking position of locking means in the padlock. Manufacture and assembly of a padlock in accordance with such a preferred embodiment is greatly simplified because a single piece of spring material is configured to provide both a yieldable shackle-locking function and a bolt means-retaining function.
Yet another feature of the present invention is the provision of a tool for removal of the bolt means relative to the padlock case. The tool is advantageously configured to move the bolt means against the second spring means to release the bolt means from a trapped, substantially immobile position within the padlock case and also to extract the bolt means during withdrawal of the tool from the padlock case.
Additional objects, features, and advantages of the invention will become apparent to those skilled in the art upon consideration of the following detailed description of a preferred embodiment exemplifying the best mode of carrying out the invention as presently perceived.